Here's my recommendation, I'm sure there will be others. Stay at Smith's Colonial motel in Hancock NY, (not so romantic) BUT it puts you almost smack dab in the middle of all the rivers.
You can get up in the morning and take a short drive to the Roscoe diner for breakfast and work your way down the Beaverkill to the East and West branch. OR you can head off to fish the West branch and work your way down to the main stem.
I actually like fishing the main stem as much as I do the other branches.
Use the search feature on here and type in Upper Delaware river.
I like Hankins and Callicoon on the main stem !!!
In 2 to 3 weeks most rivers will have a thick mat of leaves on them, take that into consideration also.
How about doing a float trip ???
https://www.smithscolonialmotel.com/